Truck resource &1 assigned to MTr &2; can only be planned with schedules

What causes this issue?

You tried to insert a vehicle resrouce to your list of vehicles in the
transportation cockpit.

System Response

The vehicle resource you selected cannot be inserted.
In the means of transport that is assigned to your vehicle resource, the
<LS>Scheduled MTr </>checkbox is selected. Therefore, the vehicle
resource can only be planned with schedules.

How to fix this error?

Choose another vehicle resource or check your Customizing settings for
the respective means of transport and decide whether the classification
of the means of transport as a scheduled means of transport is
appropriate. For more information, see
<DS:SIMG./SCMTMS/V_MTR>Define Means of Transport</>.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.